Analysis of the genomic profile of biphenotypic tumors compared to cholangiocarcinoma and hepatocellular carcinoma.

Abstract

226 Background: Biphenotypic (combined HCC/Cholangiocarcinoma) tumors represent a minority of primary liver cancers. While databases such as the Catalog of Somatic Mutations in Cancer (COSMIC) have genetic information on a large number of cases of HCC and Cholangiocarcinoma, there is little known about rarer Biphenotypic tumors. In this analysis we examine the results of targeted next-generation sequencing to assess genomic differences between these tumors. We utilize the COSMIC database for comparison. Methods: The database of theIRB-approved Washington University Hepatobiliary Registry identified patients with HCC, cholangiocarcinoma and biphenotypic tumors with specimens evaluated utilizing next generation sequencing via a Comprehensive Cancer Gene Set. Further data on corresponding genes was collected from the COSMIC database (v66) for comparison. Results: In this descriptive analysis 15 patients with biphenotypic tumors, 7 patients with HCC and 6 patients with cholangiocarcinoma are presented. The percent of samples with corresponding genetic mutations are outlined (table). These are compared to existing COSMIC data. Conclusions: Biphenotypic tumors had high levels of mutations in EGFR, P53 and Flt3. Mutations in MET, BRAF, CSF1, and MAPK1 were largely isolated to biphenotypic tumors. Mutations in CTNBB1 were isolated to cases of HCC. Notably, mutations in EGFR, Flt3 and FGFR4 were found in all three tumors in higher numbers than seen via review of COSMIC data. Overall, Biphenotypic tumors are genetically complex tumors that share many features of HCC and cholangiocarcinoma. [Table: see text]